A dissolved gas in a liquid may cause corrosion of tubes through which a liquid flows, decrease in heat exchanger effectiveness and pressure due to bubble generation, and uneven application of a liquid due to generated bubbles. Hence, depending on the method and purpose of using a liquid, degassing is required.
For example, a gas removal device disclosed in JP 11-333206 A can be used for degassing a liquid (see FIG. 9). In a gas removal device 101 shown in FIG. 9, a gas-permeable tube 103 is accommodated in a decompression chamber 102 with an inlet 111 and an outlet 112 through which the liquid to be degassed flows in and out. One end of the gas-permeable tube 103 is connected to the inlet 111 and another end is connected to the outlet 112. A vacuum suction pipe 104 reaching a bottom portion in the decompression chamber 102 is attached to the decompression chamber 102. The vacuum suction pipe 104 is connected to a vacuum suction port 113 of the decompression chamber 102. In the gas removal device 101 thus configured, the liquid to be degassed is allowed to enter from the inlet 111 and flow through the gas-permeable tube 103, and an interior of the decompression chamber 102 is decompressed by a decompression device connected to the vacuum suction port 113. Thus the liquid can be degassed.
In the gas removal device as described above, thin gas-permeable tubes are used in many cases so that they can contact with the liquid in a larger area and enhance the degassing performance. The thin gas-permeable tubes buckle sometimes when they are bent to be accommodated in the decompression chamber. In the gas-permeable tubes thus buckled, the flow resistance of the liquid to be degassed increases, and the gas removal device cannot exert its degassing performance sufficiently.